case examples for the construction of complex...
TRANSCRIPT
Project Case 1 – Urban Renewal Authority’s
Redevelopment project at Wanchai Road, H K
• Site area 7500 m2 (divided into 2 sites by the
Wanchai Road)
• the site was previous occupied by a series of pre-war
buildings or buildings that was built in the early
1960’s
• There is a 3-level basement to be built in one sites
• Foundation was carried out before the construction of
the basement
• A bottom-up method is employed for the basement
construction, with sides supported by pipe-pile/sheet
pile, and strutted by modulated strut sections.
URA’s Redevelopment at
Wanchai Road, H K
Pipe-pile as
cut-off walling
Bored-pile being
exposed at
formation level
Modulated strut
members
URA’s Redevelopment
at Wanchai Road, H K
Working platform is set up
to facilitate the basement
construction works
URA’s
Redevelopment at
Wanchai Road, H K
Basement structure
constructed using
traditional formwork
from the formation
level upward
URA’s Redevelopment
at Wanchai Road, H K
Constructing the basement
structure inside the
supported basement pit
URA’s Redevelopment
at Wanchai Road, H K
Inside the properly supported basement pit before
the construction of the main basement structure
URA’s Redevelopment
at Wanchai Road, H K
Working inside the congested basement pit
Basement wall before
erecting formwork Working
platform above
URA’s Redevelopment
at Wanchai Road, H K
Basement wall after
erecting formwork
Basement floor support
by traditional prop system
URA’s Redevelopment project at Wanchai Road, H K
Site progress as seen in Feb 2004 - basement close to its topping out at ground level
Project Case 2 – Redevelopment of Lee Garden’s Hotel
•Site area 5,750 m2
•the project required to demolish the 22-storey Lee Garden Hotel,
with a 2-level basement structure in it. A new 50-storey office
building together with a 4-level basement will be built.
•All the new foundations and the required ground strengthening and
permanent basement supporting works had to be carried out in the old
basement before it was demolished.
•The old basement could only be demolished in small sections to
allow for room and to cope with other associated works.
•When part of the basement was demolished and cleared, temporary
or sometime permanent supporting structures have to be built as soon
as possible to infill the void until the old basement was completely
replaced by the new.
•Provisions were made for the construction of the future building
including the central core in RC and part of the new basement
constructed in top-down manner.
Demolish the central part of the old
basement and excavate further
down to form a pit to construct the
raft for the core wall of the new
building
Demolition extended to the outer portion of the old basement and
raft foundation in the centre for the core wall proceeded
80% of the old basement structure being demolished, cut-off wall being
completed, and steel columns for the new tower erected in position
Close up view seeing the
construction of the new
core wall from the
completed raft foundation.
Demolition to the
remaining portion of the
basement in progress
Forming the new ground floor slab and the demolition of the
remaining portion of old basement took place at the same time
Excavation inside
the top-down
basement
Forming the ground
beams at the
formation level of the
lowest basement level
Project Case 3 – Festival Walk (Commercial Complex)
• Site area 21,000 sq m.
• Two major railway systems running nearby:
- Kowloon Canton Railway (KCR) running on one side
- Mass Transit Railway (MTR) tunnel tube running across the
site almost in the middle
• works sub-divided into two contracts
- site formation (including cut-off walling and foundation)
- basement and superstructure
• 4-level basement and 3-level semi-basement was built.
• Very shallow rockhead exists one several spots that involved a
lot of underpinning work when constructing the basement
Early stage of site formation – by the time excavation to form the
site, diaphragm wall construction and foundation works were
carried out at the same time under carefully phased manner
Forming the site and with
diaphragm wall as the side support
Protecting the MTR tunnel by forming a
cut-off bored-pile wall on the sides
Bored-pile wall
Alignment of
MTR tunnel
Early stage of the
basement construction and
the forming of an access
route into the basement to
facilitate excavation
Forming of the vehicular ramp as a means for access for
spoil removal purpose during the basement excavation process
Project Case 4 –
Cheung Kong Center (Previous Hilton Hotel)
• Overall site area: about 8000 sq m
• 5-level basement constructed using top-down
arrangement
• basement construction done in 2 stages with a lapse of
2.5 years in between
• a 36m diameter cofferdam down to -28m was
constructed to form the raft foundation for the
future building core
Forming a 36m diameter cofferdam supported with diaphragm wall panels on the sides
to facilitate the construction of the raft foundation for the core wall of the new building
Project Case 5 –
International Finance Center Phase II
• Overall site area: about 20000 sq m
• 5-level basement constructed using top-down arrangement
• basement works involved
- portion under the Main Tower
- portium under the retail podium
• a 71m diameter cofferdam down to – 35m was constructed to form the raft foundation for the building core of the Main Tower
• portion under the retail podium was constructed using top- down approach
• breaking through into the existing station concourse of the MTR lines took place inside the basement
The ground slab as the separating plate
Forming the ground floor
slab as the first separating
plate before the top-down
excavation process
Forming the remaining
portion of the ground slab
after a suspension of about 2
years as seen in early 2000
The forming of the vehicular ramp
The shaft lined by diaphragm wall forming
the vehicular ramp into the basement carpark.
The ramp serves also as an dump access
during the basement excavation process